btrfs: ioctl: reorder exclusive op check in RM_DEV

Move the op exclusivity check before the other code (same as in
ADD_DEV).

Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 11 insertions, 12 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 03df0bbb445d..45a19c6b2341 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2680,32 +2680,31 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
         if (ret)
                 return ret;
 
-        vol_args = memdup_user(arg, sizeof(*vol_args));
-        if (IS_ERR(vol_args)) {
-                ret = PTR_ERR(vol_args);
-                goto err_drop;
-        }
-
-        vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
-
         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
                         1)) {
                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
+                goto out_drop_write;
+        }
+
+        vol_args = memdup_user(arg, sizeof(*vol_args));
+        if (IS_ERR(vol_args)) {
+                ret = PTR_ERR(vol_args);
                 goto out;
         }
 
+        vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
         mutex_lock(&root->fs_info->volume_mutex);
         ret = btrfs_rm_device(root, vol_args->name);
         mutex_unlock(&root->fs_info->volume_mutex);
-        atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
 
         if (!ret)
                 btrfs_info(root->fs_info, "disk deleted %s",vol_args->name);
-
-out:
         kfree(vol_args);
-err_drop:
+out:
+        atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
+out_drop_write:
         mnt_drop_write_file(file);
+
         return ret;
 }